Vulnerability in litestar (CVE-2026-25480)
Summary
Vulnerability in litestar (CVE-2026-25480). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 2.20.0 or later.
Original description
The description as published by the source.
Summary
FileStore maps cache keys to filenames using Unicode NFKD normalization and ord() substitution without separators, creating key collisions. When FileStore is used as response-cache backend, an unauthenticated remote attacker can trigger cache key collisions via crafted paths, causing one URL to serve cached responses of another (cache poisoning/mixup)
Details
litestar.stores.file._safe_file_name() normalizes input with unicodedata.normalize("NFKD", name) and builds the filename by concatenating c if alphanumeric else str(ord(c)) (no delimiter).
This transformation is not injective, e.g.:
- "k-" and "k45" both become "k45" (because - ord('-') == 45)
- "k/\n" becomes "k4710", colliding with "k4710"
- "K" (Kelvin sign) normalizes to "K", colliding with "K"
When used in response caching, the default cache key includes request path and sorted query params, which are attacker-controlled.
PoC
import asyncio, tempfile
from litestar.stores.file import FileStore
async def main():
d = tempfile.mkdtemp(prefix="ls_filestore_poc_")
store = FileStore(d, create_directories=True)
await store.__aenter__()
# 1) ASCII ord-collision: "-" -> 45
await store.set("k-", b"A")
v = await store.get("k45")
print("k- ->", v)
print("k45 ->", await store.get("k45"))
if v == b"A":
print("VULNERABLE: 'k-' collides with 'k45'")
# 2) NFKD collision: Kelvin sign -> K
await store.set("K", b"B") # U+212A
v2 = await store.get(…
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-25480 has been found in litestar.
Risk of unauthorized operations or information disclosure.
What to do: upgrade litestar to 2.20.0 or later.
If unsure, ask your IT team or search "litestar CVE-2026-25480" on the vendor's site.
CVE-2026-25480 (litestar) — CWE-176
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 2.20.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-176) exists in litestar.
Check the vendor advisory for the affected versions of litestar.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 2.20.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'litestar' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'litestar' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
litestarを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade litestar to 2.20.0ステージング環境で 2.20.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web docs.litestar.dev
- web github.com